AsianScientist (Sep. 15, 2014) – Scientists have found the first evidence of water ice clouds on an object outside of our own solar system. These findings have been published in The Astrophysical Journal Letters.
Water ice clouds exist on our own gas giant planets—Jupiter, Saturn, Uranus, and Neptune—but have not been seen outside of planets orbiting our Sun until now.
The team used the FourStar near infrared camera at the Las Campanas Observatory in Chile to detect the coldest brown dwarf ever characterized. Over three nights, they took 151 images and combined them to reveal W0855, first seen by NASA’s Wide-Field Infrared Explorer mission and published earlier this year.
“This is a great result. This object is so faint and it’s exciting to be the first people to detect it with a telescope on the ground,” said co-author Professor Chris Tinney, of the University of New South Wales School of Physics.
Brown dwarfs are objects that are neither very small stars nor giant planets. Their temperatures can range from nearly as hot as a star to as cool as a planet, and their masses also range between star-like and giant planet-like. They are of particular interest to scientists because they offer clues to star-formation processes, and they are much easier to study than planets, because they are commonly found in isolation.
W0855 is the fourth-closest system to our own Sun, practically a next-door neighbor in astronomical distances. A comparison of the team’s near-infrared images of W0855 with models for predicting the atmospheric content of brown dwarfs showed evidence of frozen clouds of sulfide and water.
“Ice clouds are predicted to be very important in the atmospheres of planets beyond our solar system, but they’ve never been observed outside of it before now,” said lead author Dr. Jacqueline Faherty of the Carnegie Institution for Science in Washington.
The article can be found at: Faherty et al. (2014) Indications of Water Clouds in the Coldest Known Brown Dwarf.
Source: University of New South Wales; Photo: NASA/JPL-Caltech/Penn State University.
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